An electric water heater is described and wherein the bottom portion of the water holding tank is provided with various forms of electric heating elements to heat the water in the lowermost region of the tank adjacent the dome-shaped bottom wall to a temperature sufficient to prevent the proliferation of bacteria growth such as the Legionella bacteria in such lowermost region. The insulating foam support base of the water heater also provides a thermal barrier to the heating elements while biasing the heating element on the dome-shaped bottom wall in a region to insure excellent heat transfer to the cavitated zone surrounding the dome-shaped bottom wall where sedimentary deposits occur to create a culture medium for bacteria growth. In one embodiment a heating wire transfers heat to the lowermost region from the lower end of the surrounding side wall of the tank and access to the heating wire is provided for connection and removal thereof.

A circulating hot water system has a hot water flow circuit defined by pipework leading out from and back to an in-line heater, and including a pump to drive circulation of the hot water. Each of multiple user points has an outflow branch conduit and a return flow branch conduit with a common wall for heat exchange, as does the main flow circuit: the outflow conduit surrounds the return conduit. Water is fed into the system from a pressurized cold water supply main through a check valve. Sensors are used to monitor water temperatures and flow conditions around the system. A programmed control processor can control heating and pumping rates in various regimes, e.g. to maintain system temperature above a predetermined threshold. An isolation valve adapted for concentric double pipes is also described.

A control unit includes a scale detection unit for detecting, while the a burner provides combustion, occurrence of clogging with scale in a tube of a heat exchanger, and an output unit for outputting a result of a detection by the scale detection unit, a storage stores information including a numerical value representing how many times a surface temperature of the heat exchanger measured by a temperature measuring unit exceeds at least one of a plurality of threshold values. While the burner provides combustion when the surface temperature measured by the temperature measuring unit exceeds at least one of the plurality of threshold values the scale detection unit adds a predetermined value to the numerical value in the storage and when the numerical value attains a defined value or more the scale detection unit detects occurrence of clogging with scale.

A water heating apparatus includes: a water heating circuit; a heater for heating the water heating circuit; and a controller for controlling the water heating apparatus. The water heating circuit includes a heat exchanger for heating a fluid including water and hot water, and a pipe for supplying the fluid via the heat exchanger. The controller is configured to drive the heater in a cleaning mode in which a cleaning liquid for cleaning an inside of the heat exchanger is supplied to the heat exchanger through the pipe.

The present invention discloses a tubular thick film heater protection apparatus, including: an upper tube, where the upper tube includes an upper tube side surface and a toroid; an outer ring surface of the toroid is integrally connected to an upper portion of the upper tube side surface, a flange downwardly extends along an inner ring surface of the toroid, and a space between the flange and an inner side wall of the upper tube side surface forms an upper groove; and a base, where the base is provided with a lower groove, the base is provided with an elastic contact piece, and a terminal contact of the elastic contact piece can be connected to an electrode through contact; and the base is provided with a wiring terminal. The present invention further discloses a tubular thick film heater with a protection function.

The present invention discloses a tubular thick film heater protection apparatus, including: an upper tube, where the upper tube includes an upper tube side surface and a toroid; an outer ring surface of the toroid is integrally connected to an upper portion of the upper tube side surface, a flange downwardly extends along an inner ring surface of the toroid, and a space between the flange and an inner side wall of the upper tube side surface forms an upper groove; and a base, where the base is provided with a lower groove, the base is provided with an elastic contact piece, and a terminal contact of the elastic contact piece can be connected to an electrode through contact; and the base is provided with a wiring terminal. The present invention further discloses a tubular thick film heater with a protection function.

Disclosed herein are WIFI and cloud enabled temperature control systems. The temperature control systems are configured to receive user temperature settings and preferences, and control a water heater based on the user temperature settings and preferences. The temperature control systems include two or more sampling rates for enabling a higher efficiency of operation compared to conventional water heaters.

A storage water heater is provided that allows for improved maintenance of hygiene in a lower part of a hot-water storage tank and in a passage connected to the lower part of the hot-water storage tank. A storage water heater includes a heating device, a hot-water storage tank, a first passage, and a controller. The hot-water storage tank stores hot water. The first passage is connected to a lower part of the hot-water storage tank. The controller is configured to selectively switch between a heat-up operation and a recirculation operation. In the heat-up operation, hot water heated by the heating device is delivered to an upper part of the hot-water storage tank. In the recirculation operation, hot water flowing out from the upper part of the hot-water storage tank is delivered to the lower part of the hot-water storage tank via the first passage.

A water heater includes a water tank and a flow-through heating element. The water tank contains heated water. The flow-through heating element is located in the lower portion of the water tank and heats water as water is passed through an interior channel of the heating element. In another configuration, the water heater further includes a recirculation line and the heating element further includes an input end external of the water tank to receive water to be heated and an output end to output heated water into the water tank. The recirculation line transports water from the water tank to the input end of the heating element that is external of the water tank.

A hot water unit fluid supply control system for a hot water unit is disclosed. The hot water unit has a heating system that is operable in a heating cycle to heat up water in at least a first region of the water unit, and a sensor arrangement for sensing a temperature of water of the hot water unit. The control system comprises a control unit configured to: receive operational data relating to an operation of the heating system; receive temperature data from the sensor arrangement; and allow for a volume of water from the first region to be released from the hot water unit as treated water or usable water based on: the operational data, and the temperature data from the sensor arrangement.